Analytical and Experimental Investigations into the Nonstationary Response of Nonlinear Structures

9402278 Bajaj在本研究项目中，研究了非线性系统对非平稳激励的响应，得到了非线性系统参数与非平稳响应特性之间的解析关系，如最大响应幅值和幅值突然跳跃的时间。这些关系有助于针对高度非线性系统的动态特性设计隔振策略，例如旋转机械在启动过程中的响应和通过临界速度的加速度。研究方法采用传统的渐近非线性振动理论和新近发展的动态分叉理论相结合的方法。对单自由度和多自由度系统的非线性响应的幅值特性进行了解析研究，并用简谐激励下的轻阻尼梁进行了实验验证。***

9402278 Bajaj In this research project the response of nonlinear systems to nonstationary excitations is investigated leading to analytic relationships between nonlinear system parameters and nonstationary response characteristics, such as maximum response amplitude and timing of sudden jumps in amplitude. These relationships are helpful in the design of vibration isolation strategies for the dynamic characteristics of highly nonlinear systems, for example, response of rotating machinery during startup and acceleration through critical speeds. The research methodology uses a combination of the traditional asymptotic nonlinear vibration theory and the recently developed dynamic bifurcation theory. Amplitude characteristics of the nonlinear response of single and multi-degree-of-freedom systems are investigated analytically, and the results are validated experimentally using lightly damped beams subjected to harmonic excitations. ***